The present claimed invention relates to a drum brake device that facilitates an external visual confirmation of the degree of wear in the brake linings, and of a code that indicates the quality and other features of the brake shoe, without having to dismantle related parts or the device as a whole.
The decision to install new brake shoes because of excessive wear in the linings is generally based on the distance traveled and the age of the old shoes. The amount of wear will vary with the conditions of use and other factors and thus these criteria are not dispositive.
Methods known to accurately determine the amount of wear include the dismantling of the brake drum for a direct examination of the lining, or to mold a continuous shoulder on both side faces of the lining to indicate the threshold wear limit, or to mold a colored strip for use as a marker from which to ascertain the state of wear (publication of Japanese Patent Utility Model No. 1974-29346).
Brake shoes are also coded to identify the manufacturer, material, guarantee, type, or other codes (hereafter collectively referred to as code) to prevent the assembly of foreign-parts, for advertising purposes, to satisfy legal requirements, or other reasons.